Treatment of women. Sorry, but I don't like a sexist Starfleet, or your idea that a woman who isn't pretty can't have a future. Plus writing that one line "They're like animals" to describe a green skinned woman dancing to music is just bad.
You're looking at a story written in 1964 through the prism of 21st-century sensibilities. To audiences of the time, and I daresay even to many people today, it's quite understandable that Vina, with her crippled and deformed body, would prefer to stay on Talos IV where she could have the illusion of youth and beauty.
As for the Orion dance scene, IIRC, a line was cut before the pilot was shown to NBC -- something like "every now and then a man comes along who can tame one of them." So it could have been worse!